Lockstitch sewing machine



Nov. 28, 1933. F. AsHwoRTH LOCKSTITCH SEWING MACHINE Filed July 1'7, 1931 ventor :ii/@1E y U O G i M1633 @ww/ LOCKSTITCH SEWING MACHINE Filed July 17, 1931 4 Sheets-Sheetl 2 Nov. 28, 1933. F, AsHwoRTH LocxsTITcH SEWING MACHINE N0V- 28, 1933 F. AsHwoRTH LOCKSTITCH SEWING MACHINE Filed July 17, 1931 4 Sheets-Sheet 4 ses 'ist

` Patented Nov. 28, 1933 LocKsTIToH SEWING MACHINE Fred Ashworth, Wenham, Mass., assigner to u United Shoe Machinery Corporation, Paterson, N.`J., a corporation of New Jersey Application July 17,1931. Serial No. 551,418v

21 Claims.

The present inventionlfrelates to lockstitch sewing machines, and particularly to the devices embodied in such vvajmachinek for handling the n ,Y locking thread.

5 In such machines, it has been proposed to pull off the required'amount vof locking'threadgby means of a thread outlet positioned eccentrically to the axis of the shuttle.A In thus pulling off shuttle thread, however, the shuttle pulls against the stitchlock, tending to dislodge it, and thus causing irregularities in the location of the stitch locks-with relation to the` surface of the work.

vv'Th'eprincipal object Yof the present invention is to overcome this defect in the operation of lockstitch sewing machines in which the movement of the shuttle' is utilized to pull oif the' required amount of locking thread' for each stitch, and withL this objectin view, a feature of the invention contemplates the provision of a thread lock between the shuttlel and the work, arranged to be closed so as to hold 'the shuttle thread during the thread drawing movement of the shuttle. In connection with the thread lock` above `re ferred to, the invention also contemplates the against vwliich'the stitch is set. In thepreferred form of' the' invention hereinafter specifically described, the same thread lock is utilized to' lock theshuttle thread both whileV the shuttle thread is being drawn from the shuttle, and while the shuttle thread is being drawn into the work Yto set the stitch. In its broader aspects-however, this feature A of the invention is not limited to the usel of a singleY thread lock for performing both functions. Where a single thread lockvis kemployed 'it is necessary to pull the thread which has been drawn from the 'shuttle through the thread lock before the thread lock is closed prior 'to the final settingof the stitch; To secure this Iresult, a featureI of the invention contemplates the provision of means for drawing the slack shuttle thread, which has been pulled from the shuttle,-through the thread lock before the lock is -c'losed preparatory to the final setting of the stitch. In the construction 'hereinafter specifically described, this thread drawing means consists of a thread finger arranged to act upon the 'shuttle thread between the thread lock and theV work. k c Y it vis desirable that both the needle thread and the shuttle thread Ibe released at the end of a` 1sewing operation, in orderto permit the work itc be withdrawn from the machine without first severingthe threads. It isnot desirable, however,

that the shutue thread lock ibe openedV sufriprovision of a thread lock for the shuttle threadA Y the shuttle.

i ,-co ciently to wholly disengage the shuttle thread, because the withdrawal of the work from the machine under such circumstances would'tend to pull the thread away from lthe lock, thereby necessitating vthe re-threading of the lock before commencing another sewing operation. In order to avoid such a situation, a feature of the invention contemplates the Yprovision of means whereby the thread lock is opened at'the end of a sewing operation only enough to permit shuttle thread to be drawn therethrough without undue restraint while preventing the escape of thread from the lock as the work is withdrawn.

As well understood by those skilled in ther art, variations in thickness of work require corresponding variations in the length of shuttle thread drawn off forl stitch formation, and similarly, variations inxthe vfeed of the work andY variations in the depth to which the stitch lock issunk require variations in the length of shuttle I5, thread drawn off. It is therefore desirable,y in a machine in which the' stitch isset against-a shuttle thread lock,.to provide means for adjusting the length of; the shuttle thread drawn from the supply. To that` end, a feature of the invention consists in an eccentric outlet for the shuttle thread adjustable toward and from the axis of Another vfeature of the invention consists in the provision, in a shuttle, wherein a thread holder is 'removably secured by a locking memben'of aY hollow spring-pressed plunger which serves both to secure the locking member in locking position and to impart tension to the shuttle thread.

Other features of the invention consist in the construction, combinations and arrangement of parts hereinafter describedl and claimed, the adf vantages of which will lbe Iunderstoodv 4by those skilled in the art from the following.description.

VIn the drawings illustrating the invention -in its preferred form, Fig. 1 is a left side elevation of amachine embodying the several features of the invention; Fig. 2 is a right side elevation of the head of the machine; Fig. 3 is a rear elevation ofthe oscillatory shuttle and its associated mechanism; Fig. 4 is a plan View of the shuttle thread lock, the thread finger for drawing thread through 'the lock and the actuating'mechanism therefor, with the partsin the position in which theyrappear lat the end of a sewing operation; Fig. 5 is a sectional elevation taken on line -5-5y of Fig. 4; Figr' is a sectional elevation takenA on line-6 6 of Fig. 4; Fig. 7 is a sectional elevation takenon'line 7-7`of'Fig. ,4; Fig. v8 is Vaplan View illustrating the' same fparts as in Fig. .4 with `the thread lock open, and with the thread ringer at the limit of its operative movement; Fig. 9 is a sectional elevation taken on line 9--9 of Fig. 3; Figs. 10 and 11 are detail plan views oi parts of the mechanism for actuating the shuttle thread lock; Fig. 12 is a front View of the shuttle at the beginning of its advancing stroke taken on a plane at rightangles to its axis ofy rotation, and illustrating in front elevation parts or" its associated stitch forming, work supporting and work feeding instrumentalities, and illustrating in sectional elevation, a portion of the work and ay seam formed therein; Fig. i2 also illustrates the shuttle thread holder, and the shuttle thread measuring means; Fig. 13 is a diagrammatic view illustrating the shuttle at the top of its advancing or loop taking stroke, and illustrating, in front elevation, parts of its associated stitch forming, work supporting and work feeding instrumentalities, also illustrating, in sectional elevation, a portion of the work and a seam formed therein; Fig. 14 is a View similar to Fig. 13 illustrating the needle at the limit ofits advancing strokeand the shuttle at the limit of its loop taking stroke; Fig. 15 is a View similar to Figs. 13and=14 illustrating the needle nearing'the limit of its retracting stroke and the shuttle nearing the limit of its reverse stroke; Fig. 16 is a sectional elevation of the shuttle thread clamp illustrating a portion of Vthread therein, the movable clamping member being in its partially closed position which occurs when the shuttle is in the position illustrated in Fig. 13; Fig. 17 is a detail sectional elevation of the shuttle thread clamp with the movable clamping member'in its closed position which occurs when the shuttle is in the position illustrated in Fig. 13; Fig. 18Ais a detail sectional elevation offthe shuttle threadv clamp withthe movable clamping member in its open position which occurs when the shuttle is in the position illustrated in Fig. 14; Fig. 19 is adetailsectional elevation of the shuttle thread clamp with the movable clamping member in its closed position whichv occurs for the secondtiine when the shuttle is in the position indicated in Fig. 15,; Fig-20 is a detail sectional elevation of the shuttle and thread holder taken online 29-20 of Fig'.` 12; and Fig. 21 is a detail sectional elevation of the shuttle and thread holder similar to Fig.r29 illustrating the parts in position for threading.

Except as hereinafter described, the machine illustrated in the drawings is the same in the construction and arrangement and mode of operation of its various parts as the machine disclosed in the application of Bernard T. Leveque, for a lockstitch sewing machine, led February 18, 1927, Serial No. 169,203. f

The machine comprises a column 30 in the lower portion or which is mounted an electric motor 32 by which the operating parts of jthe machine are driven. The main cam shaft, or as it may conveniently be termed,'the sewing shaft is indicated at 34, and is journaled in the upper portion of Vthe column. The sewing shaft is driven from the motor through a clutch 36, horizontal shafts 38 and 40 in the base of themachine, and a vertical shaft 42. The clutch 36 is controlled from a treadle lever 44 by means o1" which the clutch may hek actuated to connect and disconnect the shafts 33'V and 40 from the source of power. i

The shoev supporting horn is indicated at'46, and is provided at its tipfwith a whirl of usual 'construction which is `driven through suitable Connections from the verticalshaft 42 as disclosed in the Leveque application above referred to.

The straight hook needle 48 and the discoidal shuttle 50 are actuated fromV the sewing shaft 34 in the same manner as in the machine of the Leveque application. The connections between the sewing shaft and needlecomprise a crank pin oiset from theforward end of the sewing shaft, a slotted lever 52 engaged by the pin, a needle actuating lever 54, a latch 56 connecting the slotted lever and the needle actuating lever, and a link connecting the-needle actuating lever to the needle bar, 58. The shuttle is driven from the needlev actuating lever 54 through Aa link which connects a downward extension from the hubof the lever to the upwardly extending arm of the shuttle actuating gear segment 60. The latch 55 is actuated from the starting and stopping treadle 44 on stopping the machine in the same manner as in the machine of the Leveque application, the release of the needle actuating lever 54 by the latch 56 taking place at that point in the cycle of operations when the needle reaches the limit of its retracting stroke.

A loop spreader' which opens the needle loo to ,facilitate the entry of the shuttle beak is indicated at 78, and consists of a suitably bent arm or nger secured to the forward end oi" a carrier bar 80, Vas disclosed in the applicants pending application for a shoe sewing lmachine filed February 9, 1929, Serial No. 338,756. To actuate the loop spreader so as to engage one side of the needle loop and separate it from the other side of the loop, the carrier bar 80 is supported by two parallel jmotion links 82 pivotally mounted at their` inner ends upon a bracket 84, forming that portion of the machine frame in which the shuttle driver shaft 86 is mounted.' The links 82 are oscillate'd by a block 88 pivotally mounted upon the pivot shaft of the shuttle actuating gear segment and rigidly connected to the gearsegnient and a suitably shaped cam-groove is formed in the block 88which is engaged by a stud projecting upwardly from the rear link 82. In order to provide clearance for a cam slide 168, hereinafter described, that portion of the carrier bar extending between the ends of the parallel motion links is upwardly offset, as illustrated in Fig. 2.

The shuttle of the illustrated machine comprises a discoidal shuttle-casing 90, the rear end of which is closed and the forwardl en d of which is open to receive a thread holder, as illustrated in the applicants pending application for a sewing machine shuttle, led May 1, 1930, Serial No. 448,909. The thread holder consists of a cylindrical thread case-92, the rear end of which is open to permit the insertion of a cop of thread while the holder is removed from the shuttle, and the front end of which, when thek thread case is in position'in the shuttle, forms a closure for the open end of the shuttle casing. From theclosed end of the'thread,holdercasing a hollow stud 94 projects inwardly so as to form a centralsupport for the inserted thread cop, anda central thread passage for vthe shuttle thread opening on the forward end of the thread holder casing.

In order to lockthe thread case securely in position in the shuttle casing 90 while permitting its ready removal, locking devices are provided as disclosed in the applicants pending application for a sewing machine vshuttle tiled May 1, 1930, Serial No. 443,919. The locking devices comprise a flange 96 projecting radially from the inner end of the thread case 92 and adapted tp engage a s lot formed in the inner wall of @geen f"is-`yieldingly held in 'position by the compression spring 1'10'postioned`wthin thenholloW stud 94, and heldbetween Aan inwardly extending 'istudahd ,ailshoulder' 11.2 .frrnedfin 'the `plunger eye 116 forrned therein. To secure the Yplate 114 firiiadjustedpositionthe 'set screw;Tv 118 is passed *through `the slot'120 formed"in the plate 114 nd received Within a tapped hole formed 'in the extension `122 of the'armf98, The disengagement of the plate 1'l4"from'v its pivotisprevented by j 'rneans 'of Aal tongue 124 `formed 'inthe' plate 114 f- 'forferigagernent with a groove 126 formed atthe VLloase of the Shoulder 128'A f orrnedv in the arm4 98. 'MQ Theshoulder' 1281s adjacent the; plate 114, and is rnade substantially Vflush'y 'therewith in' order to present 'an' even surface tothe threadloop as the `lshuttle `passes throughit. "'Ifo prevent inter- 'ffer'ence'between the set 's crevv` 118@v andthe thread 'i A45 loop-as the' shuttle passestherethrough, the plate i 114 isrecessed adjacent theY slotjv 120*y suiiiciently tof prmittheset screw to'bejpositio'nedwith its l'head inv flush relation to the 'p1ate11l4 In accordance with a feature' ofthe invention, "tensin isfapplied` to thef'shuttle thread 'by conl` pressing thelthread between"theGQringpressed 71 5h`ir'g`erv 106 and the inzierisurface* oi?-- lthe plate allas the tlflready is dravvnfrurntliethread case 792. 4Thus the plunger lfperforrns the double '55 functionE Aof i locking the' arm I 9 8 'and "imparting 'tens'ion'fto 'the' shuttle thread, thereby" obviating "the sfprevision of additional devices l for imparting the desired tensionto thethread.. 1n "aoc'ordance with the ^fefature "of 1the in yention relatingjtothe provision of "a threapllock ibetween^ the Ashuttle and the 'Work," ab1 "aol etj 130 i*constituting the fixed locking inemberjfof the th'e'ad lock, is Vsecured to the shuttle ra'cewiayjj132 f'by rneahs'of'the Vloolt I134,' a'jndwisvhe1dagainst rtationby means of'a tongue andgr'oove conf'nection `136 vof -*ordinary construction, The bracket 130 extends downwardly fr'om 'its connetinwth the raceway13'2 onjanfarc substantially coincidental With'the 'peripheryr cf ther'acey-70 "Way, and" at its lower'extrernity'is providedyvith "'a horizontal slot 138'located in Vertalali'gn'rnent with uieaxis of theshutue Themovebliokfi'ngfnienberfof the thread lockvjconsstsldf the llocking a'n 140:s e'cured;to1the' carrienplate 142 t5 tummy-'mounted 're'tiveenthe supporting plates "fiiouiied 1190.11 @51146102 ,which 1S' arranged prin 've the da nfietri'ally'-arrangedl guideway 04, forrn`e`dfinthe o uterend of thefthrea'd'case 1015592 herderV to racilitate threadingg'thearrn 98 Y14.4"a`r`1'11 146 and euidedbrthe' plate. l148T arranged .L i0? it thin @rectangular openiilel 0.11. drin `tl'iecarrierplate 142, theplat'esl44; v14 6"$=L'rf1d 148 being secured to' the under surface'hre.Shuttle, i supporting 1 bracket Aby Y means of the l screws* 150" as illustrated in Figs. 4 to 10 inclusive., y ard endet thelockng arm iisc"o`nstructed' fand arranged to enter the slot 1 38forrnedin the lbrakt' 1.30,Y .and yhas ,a thread eheaging jno'tlh, 1 5 2 formed therein; Ihe locking.. alm '.,140 fis actuated to lock the threadL betvveen'the. notch 152 and the slot 138 formed in the bracket 130 Whenthe threadi'eyell isfat'thelow'er exj'tremity of itsmovement, and (holds 'thethre'ad thus locked until the thread veye 116, has been`car- 90 ried, by the oscillationuof thefshuttle, to "the upper lirnit o f its movement.

In order tc makethe' shuttleV thradfdrawnfof by the thread eye 116'availableforlfstiteh formatio n, it iedesirable; as has been stated, toprovidey 95 neafns for drawing the 'slack v` shuttle thread through the thread lock. A'feature. ,Qi the invention consists, therefore, in a thread finger "constructed and 'arranged to vengage thelshutjtle thread betweenthe 'thread lock arid theWrk and "100 "to draw aside a bight offthread fsuiicientgifn extent to take up the slackshuttlethread measured oiby the eccentric thread eye, thextent of .'movernent of the thread ngerfbeing adjustable to accommodate it to adjustments of thei'105 thread eye. AAs illustrated, thegthread iingerconsists Iof a lever 154 pivotally uiounted'at 156 in va'lateral extension of the supporting plate1144, "said lever eXtendingdoWnWardly tofposition it betWeenthe locking arm `14() 'and the Work, 'and i110 extending laterally fromitspivot tol aposition beneath the locking arm` 1,40, 'then extending forwardly to lbring the end of the arminto'thre'ad engagingmpos'ition, 'as illustrated kin Fig. insure the 'proper' engagement'of thejjthred 1'15 vfinger with the thread, a .thread engagingihook 158 is 'formed in thefree endthereof, Ihethrew oi` the thread 'linger mayA be limited byithescrw. mountedin a'tapped hole yin the threadjiinger andarrangedjto 'abut the V supperting platef146. 120 The throw of the threadnnger vmay bejadjustedjby changing the position 'offthe screwfl' therein, 'a locking nut being provided. tojse'cure the screw infa'djusted position,- lIn'drawi'r'xgfslack thread through the thread lock, a thread Afinger '125 15.4 drawsthe thread against -a projection Vi160 f rom 'the lockingY arm 140, Which projectionfextends outwardly from the 'arm 140 atc one side vofthe thread engaging notch 152. To insurethe engagement of 'the thread with 'the proj ectionlGO, y130 thef 'projection Vis` inade long enough to `prevent jits complete jrerno'val Yfrom .thev slot 138 'duringv theuncampinemovemerit of tnearm 14o.

The present 'invention conterriiilates` thegpro- Vision of `a thread lock 'for the'shuttle thread 135 against which thefstitch is set. As herein illus trated, the' stitch `is set against the same thread llockwhich 'holds the thread during thejthread meas'uring operation,` although, 'as has` been statedythe invention ,in` its broader aspects'is net 140- flirnited to thek use Aof a single thread lock for 'performing both lockingy operations.

'As 'in the machine ofthe Leveque application above referred to, the fshu'ttlefgoes through the needle loop during the advancing or 'Work 'piere- 145 Viri'g'stroke of the needle, and the stitch 'is set 'by the Vshuttle as the shuttle reaches the top `of itsladvancing or loop taking stroke. 'Thefeccentric thre'a'dfeye 116 'pulls oi shuttle Vthread during the everse stroke of the "shuttle, "anu 15h 'contractile spring.

the thread so pulled oil remains between the thread eye and the thread -lock during the sucneeding advancingstroke of the shuttle, and at the endof the'advancing stroke the thread finger 154' drawsjthroughV the thread lock, the slack;

'shuttley thread between the thread lock and the: thread eye, Vthe thread eye at this time being positioned at the lower extremity of its movement,` as 'illustrated vby Fig. 14. During the succeeding reverse stroke of the shuttle, the thread ringer- 154 is returned to its inoperative position, and the shuttle thread between the thread lock and4 the Vwork is left slack, as illustrated byFig. 15.. As the shuttle goes through another advancing or loop taking stroke, this slack is taken up and. the stitch lock is sunk a deiinite distance intothe work, which distance is determined by the,

length or" shuttle thread pulled off by the eccentric thread eye (see Fig. 13).

, At the end of a sewing operation, the operator vmay desire to withdraw the work from the machine before severing the shuttle thread, and itis desirable to enable the operator to withdrawthe work without exercising any particular care: to prevent the escape ci" the shuttle thread from its position between the bracket 130 and the locking arm 140. To that end, a feature of the:k K. invention consists in locating the locking arm 140, at the end of a sewing operation, in the po sition indicated by Fig. 4, wherein the thread is` free to pass through the thread lock, but is held.

lagainst lateral movement relatively thereto.

The mechanism for actuating the locking arm.

V146 and the thread finger 154, as herein illus-- trated, comprises the compression springs 162' and 164 for imparting clamping movement to the arm 140, the contractile spring 1,66 for imparting thread engaging movement to the thread nger 154, and the cam slide 168 constructed and ar ranged to impart unclarnping movement to the lockingarm 140, and to impart return movementto the thread ringer 154. The compression. springs '162 and 164 are located, respectively,

, within the slots 176 and 172 formed in the car.

rier plate 142 upon which the locking arm 146 isA mounted, and are seated against the forward eX- rtremities of said notches. 1t is desirable that the Vrear ends of the compressionsprings be seated against Vvthe suppo'rtinCr plates 144 and 146, in.

order that they may impart a forward motion. to the plate 142 vand the locking arm 146. To that, end, grooves 174 and 176 are formed in the supporting plates 144 and 146, respectively, as illustrated in Figs. 6 and 7, which grooves are coinci-l dental with the slots 170 and 172, respectively, and terminate at their rear ends in shoulders which operate'to `limit the rearward movement of the compression springs. The contractile spring 166 connects the rearwardly and outwardly extending end of the thread finger l154 to the supporting 'plate `144, connections for the contractile spring comprising the bolts 178 and 160 146. The relative position of the cam surface 162V and the cani roll 164 with the thread lock open is illustrated by Figs, and the relative'position of yupon the cam roll 188 rotatably mounted on the the cam roll and cam surface at the end of a sewingoperation is illustrated by Fig. 4f The cam slide 168 imparts 'return movements to the thread 'hnger 164 by the operation of the cam surface 186 80 extended head portion of the bolt 178.

In order to operate the lock arm 140 and thread nger 154 in timed relation to the operation of vthe shuttle, the cam slide is actuated from the formed inthe cam slide 168. The cam slide is `mounted for sliding movement in guides formed icy a cross bar 194, on the plate 148, which engages a longitudinal groove 196 in the inner surrace ofthe cam slide and by a portion of the sup- `porting plate 144 which extends over one edge of the slide.

The nature and'scope of the invention having' 95 heen indicated,l and a machine embodying the several features of the invention having been :specifically described, what is claimed as the invention is 1. A lockstitch sewing machine having, in com-100 laination, a hook needle, a shuttle, a thread lock M positioned between the shuttle and the work and operative while shuttle thready is being drawn :trom the supply.

' 2,. A lockstitch sewing machine having, in-105 combination, a hook needle, a shuttle, a thread lock positioned between the shuttle and the work .and operative while shuttle thread is being drawn from `the supply, and meanspositioned between .the ythread lock and the work for drawing slack :110 :shuttle thread through the thread lock.

3. A lockstitch sewing machine having, in combination, a hook needle, a shuttle, a thread lock positioned between the shuttle and the Work and operative while shuttle thread is being drawn 1; 15 from the supply, and a thread nger positioned between the thread lock and the work for drawing slack shuttle thread through the thread lock.

' 4. A lockstitch sewing machine having, in combination, a hook needle, a discoidal shuttle hav- 120 j ing an eccentric thread outlet formed therein, a

thread lock positioned between the shuttle'and the work and operative while shuttle thread is being drawn from the supply by the shuttle.

5. A lockstitch sewing machine having, in com- 125 bination, a hook needle, a discoidalv shuttle having an eccentric thread outlet formed therein,

a thread lock positioned between the shuttle and the work and operative whilel shuttle thread is being drawn from the supply by the shuttle, and :130 means positioned between the thread lock and the work for drawing slack shuttle thread through the thread lock.

6. A lockstitch sewing machine having, in combination, a hook needle, a discoidal shuttle having aneccentric thread outletvformed therein, a thread lock positioned between the shuttle and thework and operative while shuttle thread is ,being drawn from the supply by the shuttle, and

a threadiinger positioned between the thread lock and the work for drawing slack shuttle thread through the thread lock. i

A7. In a lockstitch sewing machine, the combination with a hook needle, a shuttle and devices cooperating therewth vin forming a stitch to pull 'thread from the shuttle and pull on the needle thread against the resistance of the shuttle thread to set the stitch, of means for locking the shuttle thread between the shuttle andthe Work While the shuttle thread is being pulled is from the supply and while the stitch is being set.

8. A lockstitch sewing machine having, in combination, a hook needle, a shuttle, a'thread lock positioned between the shuttle and the work and closed while shuttle thread is being drawn from the supply, and means forV partially opening the thread lock after the completion of a sewing operation.

9. A lockstitch sewing machine having, in combination, a hook needle, a shuttle, a thread lock positioned between the shuttle and the work against which shuttle thread is drawn from the supply, and against which the stitch is set.

10. A lockstitch sewing machine having, in combination, a hook needle, a shuttle having an eccentric thread outlet formed therein, a shuttle thread lock positioned between the shuttle and the work, a thread nger positioned between the thread lock and the work, means for actuating the shuttle to cause the eccentric thread outlet to draw shuttle thread from the supply against the' thread lock, then to set the previous stitch against the thread lock, means for then opening the thread lock, and means for then actuating the thread nger to draw through the thread lock the shuttle thread 'measured off by the eccentric shuttle thread outlet.

11. A lockstitch sewing machine having, in combination, a hook needle, a shuttle, a thread lock positioned between the shuttle and the work and operative while shuttle thread is being drawn from the supply, means positioned between the thread lock and the work for drawing slack shuttle thread through the thread lock comprising a lever pivoted on the machine frame having a thread engaging surface formed therein, and means for varying the limit of operative movement of the lever.

12. A lockstitch sewing machine having, in combination, a hook needle, a shuttle, a thread lock positioned between the shuttle and the work, means for holding the thread lock closed as shuttle thread is drawn from the supply and as the stitch is set, and means for partially opening the thread lock at the end of a sewing operation.

13. A lockstitch sewing machine having, in combination, a hook needle, a shuttle, a shuttle thread lock positioned between the shuttle and the work, a thread nger positioned between the thread lock and the work, a shuttle driver, a pinion secured thereto, a rack positioned to mesh with the pinion, a cam formed in the rack, op-

nerative connections .between the cam and the thread lock for actuating the lock, a second cam formed in the rack, and operative connectionsv between the second cam and the thread nger for actuating the nger.

14. A lockstitch sewing machine having, in

combination, a hook needle, a shuttle, a shuttle thread lock positioned between the shuttle and the work, a thread nger positioned between the thread lock and the work, a shuttle driver, a pinion secured thereto, a rack positioned to mesh with the pinion, a cam formed in the rack, and

operative connections between the cam and the thread lock for actuating the lock.

15. A shuttle for shoe sewing machines comprising a shuttle casing, a thread holder, a locking member for removably securing the thread holder within the shuttle casing, and a plate admember for removably securing the thread holder within the shuttle, and a platev adjustably se- Y cured tothe locking member provided with a Y thread eye adjustable toward and from the axis of the shuttle bythe adjustment of the plate.

17. A shuttle for shoe sewing machines comprising a shuttle casing, a thread holder, a locking member for removably securing the thread holder within the shuttle casing, and a plate pivoted on the locking member provided with a thread outlet adjustable toward and from the axis of the shuttle by a pivotal movement of the plate.V

18. A shuttle for shoe sewing machines comprising a discoidalshuttle casing having an open end, a Vremovable thread holder comprising a cylindrical casinghaving an end forming a closure for the open end of the shuttle casing, a hollow stud extending inwardly from the end of the thread holder and forming a passage for conducting thread out of the thread holder, a locking vmember for removably securing the thread holder within the shuttle casing, means for securing the locking member in locking position comprising a hollow spring pressed plunger posivtioned in the hollow stud, a plunger engaging surface formed in the locking member, and means for applying tension to the shuttle thread comprising a thread engaging surface formed in the plunger, and a cooperating thread engaging surface formed in the locking member.

19. A lockstitch sewing machine having, in combination, a hook needle, a discoidal shuttle having an Veccentric thread outlet formed therein, a needle lever and connections for actuating the needle, connections between said lever and the shuttle for oscillating the shuttle, and a shuttle thread lock positioned between the shuttle andthe work and operative while shuttle thread is being drawn from the supply by the shuttle.

20. A lockstitch sewing machine having, in combination, a hook needle, an oscillatory discoidal shuttle having an eccentric thread outlet formed therein, means for actuating the needle and shuttle timed to cause-the shuttle to pass through the needle loop during the advancing stroke of the needle, and a shuttle thread lock positioned between the shuttle and the work vand operative while shuttle thread is being drawn from the supply by the shuttle.

21. A lockstitch sewing machine having, in combination, a 4hook needle, an oscillatory discoidal shuttle having an eccentric thread outlet lever and the shuttlefor actuating the shuttle `timed to cause the shuttle to pass through the needle loop during the advancing stroke of the needle. v

' FRED ASHWORTH. 

